Nonionic surfactant compositions

ABSTRACT

The present invention provides nonionic surfactants, compositions incorporating these surfactants, and related methods of making and using such surfactants and compositions. The nonionic surfactants demonstrate excellent equilibrium and dynamic surface tension properties as well as excellent wetting properties. Further, representative embodiments of the surfactants have shown low foaming characteristics, indicating that the surfactants would be suitable in applications where resistance to foaming is desired. The surfactants can be used singly or in combination with other nonionic and/or ionic surfactants as desired. As an over view, the nonionic surfactants of the present invention have a structure in which the surfactant backbone includes one or more amine moieties. At least one, preferably two or more branched, cyclic, fused cyclic, and/or spyro hydrophobic moieties are pendant from at least one of the amine moieties. Additionally, at least one, preferably two or more hydrophilic moieties, preferably alkylene oxide (i.e., polyether) chains also are pendant from at least one of the amine moieties.

PRIORITY

This application claims priority to International Application No.PCT/US2013/026088, filed on Feb. 14, 2013, which in turn claims priorityunder 35 U.S.C. §119(e) to U.S. provisional application No. 61/598,469,titled “NONIONIC SURFACTANT COMPOSITIONS,” filed Feb. 14, 2012, whereinthe disclosures of these applications are incorporated herein byreference in their respective entireties for all purposes.

FIELD OF THE INVENTION

The present invention relates to nonionic surfactants. Moreparticularly, the present invention relates to nonionic surfactantscomprising one or more amine moieties, one or more branched hydrophobicchains pendant from the amine moieties, and one or more hydrophilicalkylene oxide chains pendant from the amine moieties.

BACKGROUND OF THE INVENTION

The ability to reduce the surface tension of liquid compositions,particularly aqueous compositions, is of great importance in a widevariety of compositions including solutions, dispersions, gels,emulsions, latex compositions, and the like. Such compositions are usedin a wide range of applications including paints and other coatings,stains and other coloring agents, ink compositions, oil and gas recoverycompositions, steam assisted gravity drainage compositions, chemicalflooding compositions, cosmetics, foods, nutriceuticals, health careproducts, cleaning products, etching compositions, agrochemicals, or thelike.

It is well known in the art that so-called Gemini surfactants, which aresurfactants with multiple hydrophobic tails and multiple hydrophilicheads, or Gemini-like surfactants exhibit superior properties comparedto those of analogous conventional surfactants. See, e.g., GeminiSurfactants: Synthesis, Interfacial and Solution-Phase Behavior, andApplications, Vol. 117, Zana, R.; Xia, J., Eds.; Marcel Dekker: NewYork, 2004. Furthermore, it is also well known in the art thatincreasing branching in a hydrophobic tail significantly improveswetting properties of a surfactant. See, e.g., Rosen, M. J. Surfactantsand Interfacial Phenomena, 3^(rd) ed.; John Wiley & Sons, Inc.; Hoboken,N. J., 2004; pp. 243-277.

Important surfactant performance characteristics include equilibriumsurface tension properties, dynamic surface tension properties, wettingproperties, foaming properties, and the like. Equilibrium surfacetension is important when a system is at rest. Dynamic surface tensionis a fundamental property which measures the ability of a surfactant toperform under high speed application conditions. Many nonionicsurfactants may have acceptable equilibrium surface tension properties,but demonstrate poor dynamic surface tension properties. Many nonionicsurfactants also tend to be foamy and make compositions too susceptibleto foaming, which can be undesirable in many applications. Theimportance of improving equilibrium, dynamic, wetting and foamingperformance is well-appreciated in the art.

Accordingly, there is a strong demand for nonionic surfactants thatprovide not only strong equilibrium surface tension properties but alsostrong dynamic surface tension properties and strong wetting propertieswith a reduced tendency to cause foaming.

SUMMARY OF THE INVENTION

The present invention provides nonionic surfactants, compositionsincorporating these surfactants, and related methods of making and usingsuch surfactants and compositions. The nonionic surfactants demonstrateexcellent equilibrium and dynamic surface tension properties as well asexcellent wetting properties. Further, representative embodiments of thesurfactants have shown low foaming characteristics, indicating that thesurfactants would be suitable in applications where resistance tofoaming is desired. The surfactants can be used singly or in combinationwith other nonionic and/or ionic surfactants as desired.

As an overview, the nonionic surfactants of the present invention have astructure in which the surfactant backbone includes one or more aminemoieties. At least one, preferably two or more branched, cyclic, fusedcyclic, and/or spyro hydrophobic moieties are pendant from at least oneof the amine moieties. Additionally, at least one, preferably two ormore hydrophilic moieties, preferably alkylene oxide (i.e., polyether)chains also are pendant from at least one of the amine moieties.

In one aspect, the present invention relates to a method of making anonionic surfactant, comprising the steps of:

-   -   a) providing an adduct comprising at least one secondary amine        moiety and at least two branched, cyclic, fused cyclic, and/or        spyro hydrophobic moieties; and    -   b) N-functionalizing at least a portion of the secondary amine        moieties of the adduct under conditions effective to convert at        least a portion of the secondary amine moieties to tertiary        amine moieties having pendant, hydrophilic, N-ether        functionality.

In another aspect, the present invention relates to a nonionicsurfactant of the formula(E)_(m)-A¹-(R¹)_(n)

-   -   wherein:        -   A¹ is an (n+m) valent moiety comprising at least one            tertiary amine moiety and optionally one or more secondary            amine moieties;        -   each R¹ independently is a branched, cyclic, fused cyclic,            and/or spyro hydrophobic moiety;        -   each E independently is H or an N-functional, monovalent            moiety of the formula            —R²—(R³O)_(x)—R⁴    -   with the proviso that at least one E is not H, wherein each R²        independently is a single bond or a divalent linking group; each        R³ is independently an alkylene moiety containing from 1 to 5        carbon atoms (e.g., each alkylene oxide chain independently may        contain one or more different kinds of alkylene oxide units used        in combination; and each alkylene oxide chain may be the same or        different than other such chains included in the molecule); each        x independently is 1 to 100; and each R⁴ independently is H or a        monovalent moiety comprising from 1 to 8 carbon atoms;        -   n is 2 to 6; and        -   m is 1 to 6.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

The embodiments of the present invention described below are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principles and practices of the presentinvention. All patents, pending patent applications, published patentapplications, and technical articles cited herein are incorporatedherein by reference in their respective entireties for all Purposes.

The present invention relates to nonionic surfactants of the formula(E)_(m)-A¹-(R¹)_(n)

wherein:

-   -   A¹ is an (n+m) valent moiety comprising at least one, more        preferably at least two tertiary amine moieties, and optionally        one or more secondary amine moieties;    -   each R¹ independently is a branched, cyclic, fused cyclic,        and/or spyro hydrophobic moiety;    -   each E independently is H or an N-functional, monovalent moiety        of the formula        —R²—(R³O)_(x)—R⁴    -   with the proviso that at least one E is not H and more        preferably at least two E are not H, wherein each R²        independently is a single bond or a divalent linking group; each        R³ is independently a linear or branched alkylene moiety        containing from 1 to 5 carbon atoms (e.g., each alkylene oxide        chain independently may contain one or more different kinds of        alkylene oxide units used in combination; and each alkylene        oxide chain may be the same or different than other such chains        included in the molecule); each x independently has an average        value of 1 to 100; and each R⁴ independently is H or a        monovalent moiety comprising from 1 to 8 carbon atoms;        -   n is 2 to 6, preferably 2 to 3, more preferably 2; and        -   m is 1 to 6, preferably 1 to 3, more preferably 1 to 2.

Preferably, each of n and m independently are 2 to 4. In someembodiments, n=m. Even more preferably, each of n and m are 2.

As used herein, a hydrophobic moiety refers to a moiety in which theratio of carbon atoms to hetero atoms (such as O, P, S or the like) inthe moiety is 5:1 or greater, preferably 8:1 or greater, more preferably12:1 or greater. Even more preferably, a hydrophobic moiety is ahydrocarbyl or hydrocarbylene moiety that (1) contains at least 5 carbonatoms, (2) contains only C and H atoms, (3) is free of hetero atoms suchas O, P, and S or the like; and (4) optionally is branched and/or has aring, spyro, and/or fused ring structure.

As used herein, the terminology “N-functional” means that a moiety ispendant from a nitrogen atom.

In exemplary embodiments, each R³ moiety independently may be ethylene,propylene, isopropylene, butylene, isobutylene, or combinations thereof.Preferably, each R³ moiety is ethylene, propylene, butylene orcombinations thereof. More preferably, R³ is ethylene.

As shown by the general formula, the value for x may be selected over awide range. In preferred embodiments, each x independently has anaverage value of 1 to 20, preferably 1 to 10, more preferably 1 to 4.When a surfactant includes 2 or more E moieties, it is desirable thatthe values for x for all the E moieties are generally matched onaverage. For instance, if a surfactant embodiment has two E moieties andone of the E moieties has an average x=4, then it is desirable that theother E has an average x=3 to 5, more preferably x=3.5 to 4.5, morepreferably x=4.

A first, preferred class of surfactants of the present invention may berepresented by the general formula

wherein E and R¹ are as defined above, and R is a divalent linkinggroup. One exemplary first group of surfactants according to this firstclass includes surfactants according to the following formula:

wherein E and R are as defined above, wherein R preferably is a divalentmoiety that may be linear, branched, cyclic, fused cyclic, spyro,saturated or unsaturated, aliphatic or aromatic, substituted orunsubstituted, and more preferably is a hydrocarbylene moiety of 1 to 20carbon atoms; each R⁵ and each R⁶ independently is H, a monovalenthydrocarbyl moiety comprising 1 to 20 carbon atoms, or a co-member of ahydrocarbylene ring structure with at least one other R⁵ or R⁶, with theproviso that at least one R⁵ and at least one R⁶ is not H; and each rindependently is 0 to 20.

More preferably, the first group of surfactants is exemplified bysurfactants having the formula

and/or of the formula

wherein each E independently is as defined above, and in the formula forE, R² is a single bond and R³ independently is selected from one or moreof ethylene, propylene, butylene or combinations thereof.

A particularly preferred embodiment of a surfactant of the type shown inParagraph 19 has the formula

wherein when dynamic properties are to be favored, each of x and y is onaverage independently 0 to 6, preferably independently 0 to 4, with theproviso that x+y on average is 1 to 12, preferably 1 to 8. Comparableversions of the surfactants described in paragraphs 20 and 21independently would have similar structures for each E to favor dynamicproperties. More generally, to favor dynamic properties for thesurfactants of the first class of surfactants of Paragraph 16 above orthe second class of surfactants of Paragraph 29 below, each Eindependently generally includes on average from 0 to 6, preferably from0 to 4 ethylene oxide units, with the proviso that the total number ofethylene oxide units in all the E moieties of the surfactant on averageis 1 to 12, preferably 1 to 8.

In other embodiments of the first class of surfactants of Paragraph 16above or the second class of surfactants of Paragraph 29 below moresuitable for oil and gas applications or the like, each E independentlyincludes a combination comprising ethylene oxide (EO) and optionally andpreferably propylene oxide (PO) moieties, wherein the molar ratio of EOto PO moieties (when PO moieties are present) in each E independently isin the range from 100:1 to 1:100, desirably 20:1 to 1:20; the averagenumber of EO units in each E independently is in the range from 1 to100, preferably 1 to 50; and the average number of PO units in each E isin the range from 0 to 100, preferably 0 to 20; and the total number ofEO and PO units in the E moieties is in the range from 1 to 200,preferably 1 to 100, more preferably 1 to 70.

An exemplary second group of surfactants according to the first class ofsurfactants includes surfactants according to the following formula:

wherein each R⁷ and each R⁸ independently is a monovalent moietycomprising 1 to 20 carbon atoms or is a co-member of a ring structure;each R⁹ independently is H, a monovalent moiety comprising 1 to 20carbon atoms, or a co-member of a ring structure; and each tindependently is 1 to 20, preferably 1 to 6. A particularly preferrednonionic surfactant of this type has the formula

An exemplary third group of surfactants according to the first class ofsurfactants includes surfactants according to the following formula:

wherein each R¹⁰ and each R¹¹ independently is a monovalent moietycomprising 1 to 20 carbon atoms or is a co-member of a ring structure;each R¹² independently is H, a monovalent moiety comprising 1 to 20carbon atoms, or a co-member of a ring structure; and each qindependently is 1 to 20. A particularly preferred nonionic surfactantof this type has the formula

A second, representative class of surfactants of the present inventionmay be represented by the general formula

wherein each R¹³ and each R¹⁴ independently is a monovalent moietycomprising 1 to 20 carbon atoms or is a co-member of a ring structure;and each b independently is 0 to 20. A particularly preferred nonionicsurfactant of this tune has the formula

The surfactants of the present invention have the ability to reduce thesurface tension of water. For instance, using illustrative embodimentsof the surfactants at 0.1 weight percent concentration in water shouldprovide solutions with an equilibrium surface tension of less than 50mN/m. The dynamic surface tension of such illustrative embodiments wouldbe less than 55 mN/m at bubble rate of 5 bubbles/second. Desirably, thecontact angle on a Teflon film should be less than 75 degrees for morepreferred embodiments.

The surfactants of the present invention can be used singly or incombination with other surfactants of the present invention or withother surfactants in a wide range of applications. The surfactants maybe used in aqueous or nonaqueous compositions including solutions,dispersions, emulsions, latex compositions, gels, or the like. Thesurfactants would be particularly useful in any application in which lowfoaming, nonionic wetting agents are desired. For example, thesurfactants would be useful in paint and other coating compositions, inkcompositions, adhesive compositions, oil and gas recovery compositions,steam assisted gravity drainage compositions, chemical floodingcompositions, cosmetics, foods, nutriceuticals, health care products,cleaning products, staining products, etching compositions, agrochemicalcompositions, or the like.

According to a preferred methodology for preparing nonionic surfactantsof the present invention, a first step involves providing at least oneadduct comprising at least one secondary amine moiety and at least two,branched hydrophobic moieties. In a second step, at least a portion ofthe secondary amine moieties of the adduct are N-functionalized underconditions effective to convert at least a portion of the secondaryamine moieties to tertiary amine moieties having pendant, hydrophilic,N-ether functionality and thereby form the nonionic surfactant of thepresent invention described above.

As used herein, N-functionalized means that that the functionality iscaused to be pendant from the nitrogen of the amine moiety, convertingit from a secondary amine to a tertiary amine. N-ether means that theether is pendant directly or indirectly from the resultant tertiaryamine.

The adduct provided in the first step generally has the formulaA-(R¹)_(n)wherein A is an n-valent moiety comprising one or more secondary aminemoieties; each R¹ independently is as defined above such as a branched,hydrophobic moiety or is a member of a hydrophobic ring structure withanother R¹; and n is 2 to 10, preferably 2 to 6. In illustrativeembodiments, the adduct comprises a compound having a formula selectedfrom the following or is a combination thereof:R¹—NH—R¹;R¹—NH—R—NH—R¹; and/or(R¹—NH)_(p)—R¹⁵,wherein each R¹ independently is as defined above such as a branched,hydrophobic moiety or a co-member of a hydrophobic ring structure withanother R¹; R is a divalent linking moiety as defined above; R¹⁵ is ap-valent moiety; and p is 3 to 10.

One representative class of adducts of the present invention has theformula

wherein R, R⁵, and R⁶ are independently as defined above. One preferredadduct according to this formula has the structure

Another preferred adduct according to this formula has the structure

Another representative class of adducts of the present invention has theformula

wherein each of R⁷, R⁸, and R⁹ independently is as defined above. Onepreferred adduct according to this formula has the structure

Another representative class of adducts of the present invention has theformula

wherein each R¹¹, R¹², and R¹³ independently is as defined above. Onepreferred adduct according to this formula has the structure

Another representative class of adducts of the present invention has theformula

wherein each R¹³ and each 14 independently is as defined above. Onepreferred adduct according to this formula has the structure

The adduct can be prepared by reacting ingredients comprising first andsecond compounds under conditions effective to form the adduct, whereinthe first compound comprises one or more ketone and/or aldehyde moietiesand the second compound comprises one or more primary amine moieties.Illustrative conditions for forming the adduct from such first andsecond reactant compounds include reductive amination conditions.Reductive amination techniques are further described in (1) “ThePreparation of Amines by Reductive Alkylation”, Emerson, W., OrganicReactions, Vol. 4, 174-255 (1948); (2) “Reductive Aminations of CarbonylCompounds with Borohydride and Borane Reducing Agents”, Baxter E. W.;Reitz, A. B., Organic Reactions, Vol 59, 1-714 (2002); (3) Abdel-Magidet al. Org. Process Res. Dev. 2006, 10, 971-1031; (4) Abdel-Magid et al.J. Org. Chem. 1996, 61, 3849-3862.

The hydrophobic, branched moieties may be sourced from either the firstand/or second compounds. The first and/or second compounds can besymmetric or asymmetric. The first and/or second compounds can belinear, branched or cyclic; aliphatic or aromatic; and may be saturatedor unsaturated. The first and/or second compounds preferably may includefrom 3 to 24 carbon atoms with the proviso that at least one of thefirst and second compounds provides a source of the branched hydrophobicmoiety to be incorporated into the resultant adduct.

The first compound can include any one or more compounds that includeone or more ketone and/or one or more aldehyde moieties. Exemplaryaldehydes include 2-ethylhexanal, glyoxal, 2-ethylhex-2-enal,2-propylhept-2-enal and 2-methylpent-2-enal, 2-propylheptanal,benzaldehyde, cinnamaldehyde, acetaldehyde; and combinations of these.Exemplary ketones include methyl isobutyl ketone, di-isobutyl ketone,cyclohexanone, 1,4-cyclohexanedione, 1,2-cyclohexanedione,1,3-cyclohexanedione, acetone, methyl ethyl ketone, di-isopropyl ketone,2,6,8-trimethylnonan-4-one, 2-pentanone, 2-hexanone, 2-heptanone,2-octanone, and combinations of these.

In addition to the ketone and/or aldehyde moiety, the first compound mayoptionally include one or more other kinds of functionality that arecompatible with the reductive amination and that would not undulycompromise the subsequent alkoxylation on the next reaction stage and/orunduly compromise performance of the resultant surfactant. Examples ofsuch optional functionality include hydroxyl, alkenyl, alkynyl,secondary and tertiary amine, amide, ether, thioether and thiolmoieties.

The second compound may include any one or more compounds including oneor more primary amine moieties. Exemplary primary amines include one ormore of 1,2-ethylene diamine, 1,3-propylene diamine,1,2-cyclohexyldiamine, 1,3-cyclohexyldiamine, 1,4-cyclohexyldiamine,p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, 2-ethylhexylamine, 2-propylheptyl amine, 2,4,4-trimethylpentan-2-amine,isopropylamine, isobutylamine, isopentylamine and combinations thereof.

In addition to the primary amine moiety, the first compound mayoptionally include one or more other kinds of functionality that arecompatible with the reductive amination and that would not undulycompromise the subsequent alkoxylation on the next reaction stage and/orunduly compromise performance of the resultant surfactant. Examples ofsuch optional functionality include secondary and tertiary aminemoieties, hydroxyl, alkenyl, alkynyl, amide, ether, cyano, nitro,thioether and thiol moieties.

Reductive amination typically takes place in the presence of one or morereducing agents. Any such agent(s) known to be useful for reductiveamination may be used in the practice of the present invention.Exemplary reducing agents include borohydride systems such as sodiumborohydride, sodium triacetoxyborohydride and sodium cyanoborohydride aswell as hydrogenation catalysis systems such as palladium, platinum,rhodium, ruthenium and nickel-based catalyst systems under H₂ pressure.

According to a representative reaction scheme, the first compound andsecond compound are placed into a suitable reaction vessel in a suitablesolvent in the presence of the reducing agent. The reaction may becarried out on a batch or continuous basis as desired. The stoichiometrymay be selected so that the first compound is in excess so that thefirst compound end caps the second compound. In other modes of practice,the stoichiometry is selected so that the second compound end caps thefirst compound. In some instances, the stoichiometry may besubstantially 1:1. In still other modes of practice, alternativestoichiometries may be practiced to achieve other reaction goals.

The reaction is allowed to progress at a suitable temperature for asuitable time period often under a protected atmosphere. By way ofexample, allowing the reaction to proceed at room temperature under anitrogen atmosphere for 10 to 36 hours would be suitable.

After the reaction is complete, the reaction may be quenched, and theproducts may be extracted into an organic phase. A high purity productcan then be recovered from the organic phase using any desired recoverytechniques.

According to an alternative strategy, the adduct can be provided byusing reductive amination techniques to form the adduct from one or morecompounds that include at least one primary amine moiety and at leastone aldehyde and/or ketone moiety. These compounds are multifunctionalin the sense that they contain at least two different kinds offunctionality, namely a primary amine and at least an aldehyde and/orketone in the same compound. In other modes of practice, the adduct canbe formed from reactants including at least one of the first and/orsecond compounds described above and at least one multifunctionalreactant compound.

To prepare a nonionic surfactant of the present invention, one or moreadducts provided in the first step are N-functionalized via a reactionstrategy that adds respective hydrophilic moieties to one or more of thesecondary amine moieties of the adduct(s). The moieties independentlymay be hydrophilic ether or polyether moieties containing, by way ofexample, 1 to 200 ether units, added independently to one or more of thesecondary amines of the adduct(s). In more preferred embodiments, two ormore of the secondary amines of the adduct(s) are N-functionalized withhydrophilic moieties. In some modes of practice, the degree offunctionalization of the secondary amines is matched as closely aspractical on average. For example, if two or more amines arefunctionalized by hydrophilic groups, it is desired that the averagedegree of functionality of a first a first amine moiety is X₁, then itis desired that the average degree of functionality of the otherfunctionalized amines is at least 50%, or even at least 70%, or even100% of X₁.

By way of example, consider a surfactant embodiment containing twotertiary amines functionalized with —(CH₂CH₂O)— (ethylene oxide) groups.If the first amine moiety is functionalized with an average of 4ethylene oxide groups, then it is desired that the other amine also isfunctionalized with 2 to 8, preferably 2.8 to 5.7, preferably 5 ethyleneoxide groups.

According to one illustrative mode of practice, the secondary aminemoieties of the adduct(s) are N-functionalized under suitable conditionsto convert the secondary amine moieties to tertiary amine moietieshaving directly or indirectly pendant N-ether (or N-polyether)functionality. Representative conditions include reacting the adduct(s)with one or more epoxy functional compounds such as those including from2 to 12 carbon atoms. Examples of such compounds include one or more ofethylene oxide, propylene oxide, butylene oxide, and combinationsthereof.

The N-functionalization of the amines with these compounds to providependant ether or polyether chains is known in the art as alkoxylation.As known in the art, alkoxylation may involve alkoxylation with morethan one type of resultant alkylene oxide. Thus, the alkylene oxideunits may be the same or different. If different, the alkylene oxideunits may be random or arranged in blocks.

An amine may be alkoxylated by any desired number of alkylene oxideunits. In representative embodiments, at least one amine of an adduct,preferably at least two amines of each adduct is alkoxylated with 1 to100, preferably 1 to 20, more preferably 1 to 6 alkylene oxide units.

The alkoxylation reaction desirably occurs in the presence of acatalyst, optionally in a suitable solvent. The catalyst may be anycatalyst or combination of catalysts known to be useful for carrying outalkoxylation reactions. Representative examples include KOH, NaOH, KH,NaH and double metal cyanide (DMC) catalysts. Suitable solvents also arewidely known and any may be used. Examples include dimethoxyethane andtoluene.

According to a representative alkoxylation methodology, an adduct,solvent and catalyst are loaded into a suitable reaction vessel. Anexemplary reaction vessel is pressurized to facilitate the reaction. Thereaction may occur on a batch or continuous basis. The desired epoxyfunctional reactant may then be supplied at the desired stoichiometricexcess to achieve the desired functionalization. For instance, 4equivalents of epoxide can be supplied per equivalent of amine toachieve an average functionalization of 4 alkylene oxide units peramine. The reaction is allowed to proceed at elevated pressure andtemperature until complete. The reaction product can then be recoveredusing conventional recovery techniques.

The present invention will now be further described with reference tothe following illustrative examples.

Example 1

Methyl isobutyl ketone (MIBK) (6.050 g, 60.403 mmol, 1 equiv.), ethylenediamine (1.815 g, 30.202 mmol, 0.5 equiv.) and sodiumtriacetoxyborohydride (15.362 g, 72.484 mmol, 1.2 equiv.) in about 175mL CH₂Cl₂ were weighed into a 500 mL three-necked flask. The mixture wasstirred at room temperature under a nitrogen atmosphere. The reactionwas stopped after a total of 20 h. The mixture was quenched withsaturated aqueous NaHCO₃ and the product extracted into ethyl acetate.The combined organic fraction was dried over sodium sulfate, filteredand evaporated using a rotovap to yield 3.774 g of desired product. Theproduct, N,N′-bis(4-methylpentan-2-yl)ethane-1,2-diamine, had highpurity as determined by gas chromatography and NMR. This adduct has thefollowing structure:

Example 2A

N,N′-bis(4-methylpentan-2-yl)ethane-1,2-diamine (1.00 g, 4.38 mmol, 1equiv.), 1,2-dimethoxyethane (1 mL), KH (3-5 mg, 0.3-0.5 wt. %) wereloaded into a glass PPR vial (insert). Alkoxylation was carried out in aSymyx PPR® (Parallel Pressure Reactor) setup containing 48 reactors.Ethylene oxide (EO) was delivered via an Isco syringe pump equipped witha robotically-controlled needle and compressed gas microvalve connectedto the PPR, such that 4 equivalents of EO were added per molecule ofdiamine initiator on average. A glass insert along with a removable PEEKstir paddle for the cell were dried in a vacuum oven at 125° C.overnight. The insert with the diamine, 1,2-dimethoxyethane and KH wasloaded into each PPR well, heated to 130° C., and pressurized withnitrogen to 50 psi. EO was introduced at 130° C. and the reaction wasstirred for 12 h at that temperature. After cooling and venting, theinsert was placed in a Savant SC250EXP SpeedVac® Concentrator for 1 h at80° C. and 0.01 Torr. The resulting viscous surfactant was tested forits properties without additional purification. The identity of thesurfactant was confirmed by NMR spectroscopy. The ethoxylated surfactantof this Example 2A has the following structure where the sum of x+y=4 isan average:

Example 2B

The procedure of Example 2A is repeated to prepare a surfactant, excepta catalyst is not used.

Example 2C

The procedure of Example 2A is repeated to prepare a surfactant, excepta solvent is not used.

Example 3

Basic surfactant properties of the surfactant from EXAMPLE 2A werecharacterized. The equilibrium surface tension of a 0.1 wt % aqueoussolution is reduced to 29 mN/m, and the dynamic surface tension at 5bubbles/second is 37 mN/m. The contact angle on a TEFLON film is reducedto 70 degrees, and the contact angle on polyethylene is reduced to 46degrees. As summarized in table 1 below, the ethoxylated diaminesurfactant from EXAMPLE 2A exhibits better properties than thenon-ethoxylated precursor prepared in Example 1.

Basic surfactant properties also were characterized on thenon-ethoxylated precursor from EXAMPLE 1. The equilibrium surfacetension of a 0.1 wt % aqueous solution is reduced to 36 mN/m, thedynamic surface tension of a 0.1 wt % aqueous solution at 5bubbles/second is 37 mN/m, the contact angle on a Teflon film is 90degrees, and the contact angle on polyethylene is 62 degrees. Data issummarized in the following Table 1.

TABLE 1 Comparison of basic surfactant properties of non-ethoxylateddiamine-based molecule with those of the corresponding ethoxylatedversion. Example 1 Precursor EXAMPLE 2 aqueous solution aqueous solution(0.1 wt %) (0.1 wt %) Equilibrium surface tension, 36 29 mN/m DynamicSurface Tension at 5 37 40 bbl/sec, mN/m Contact angle on 62 46polyethylene, degree Contact angle on Teflon, 90 70 degree

Example 4

MIBK (6.843 g, 59.93 mmol, 1 equiv.), 2-ethylhexyl amine (7.745 g, 59.93mmol, 1 equiv.) and sodium triacetoxyborohydride (17.780 g, 84.37 mmol,1.4 equiv.) were weighed into a 500 mL three-necked flask and suspendedin about 175 mL CH₂Cl₂. The mixture was stirred at room temperatureunder a nitrogen atmosphere for 64 h after which time the reaction wascomplete. The mixture was then quenched with saturated aqueous NaHCO₃and the product extracted into ethyl acetate. The combined organicfraction was dried over sodium sulfate for 5 h. After filtration, thesolution was rotovaped to give 10.775 g of the desired product as aslightly yellow liquid. GC analysis of the isolated product showedpurity of 98%.

Example 5

1,4-Cyclohexanedione (3.037 g, 27.08 mmol, 1 equiv.), 2-ethylhexyl amine(7.000 g, 54.16 mmol, 2 equiv.) and sodium triacetoxyborohydride (13.775g, 65.00 mmol, 1.2 equiv.) were weighed into a 500 mL three-necked flaskand suspended in about 160 mL CH₂Cl₂. The mixture was stirred at roomtemperature under a nitrogen atmosphere for 22 h after which time thereaction was complete. The mixture was then quenched with saturatedaqueous NaHCO₃ and the product extracted into ethyl acetate. Thecombined organic fraction was dried over magnesium sulfate for 5 h.After filtration, the solution was rotovaped to give 7.232 g of thedesired product as a dark brown liquid. GC analysis of the isolatedproduct showed purity of 98%.

Example 6

MIBK (6.130 g, 61.202 mmol, 1 equiv.), 1,2-diaminocyclohexane (3.494 g,30.601 mmol, 0.5 equiv.) and sodium triacetoxyborohydride (15.565 g,73.442 mmol, 1.2 equiv.) were weighed into a 500 mL three-necked flaskand suspended in about 175 mL CH₂Cl₂. The mixture was stirred at roomtemperature under a nitrogen atmosphere for 19 h after which time thereaction was complete. The mixture was then quenched with saturatedaqueous NaHCO₃ and the product extracted into ethyl acetate. Thecombined organic fraction was dried over magnesium sulfate for 5 h.After filtration, the solution was rotovaped to give 8.490 g of thedesired product as an off-white paste. GC analysis of the isolatedproduct showed purity of 94%. ¹H NMR (CD₃OD, 500 MHz, RT): δ=0.84-0.96(m, 12H), 1.03-1.78 (m, 14H), 1.12-1.20 (m, 6H), 2.10-2.18 (m, 1H),2.43-2.58 (m, 1H), 2.88-3.12 (m, 2H). The following shows the structuresof precursors from EXAMPLES 4-6, respectively.

Examples 7-9

The corresponding amine or diamines from Examples 4-6, respectively,(1.00 g), 1,2-dimethoxyethane (1 mL) (the reaction may be conductedwithout solvent), and KH (3-5 mg, 0.3-0.5 wt. %) (the reaction may alsobe carried out without any catalyst) were loaded into a glass PPR vial(insert). Alkoxylation was carried out in a Symyx PPR® (ParallelPressure Reactor) setup containing 48 reactors. Ethylene oxide (EO) wasdelivered via an Isco syringe pump equipped with arobotically-controlled needle and compressed gas microvalve connected tothe PPR, such that required equivalents of EO were added per molecule ofamine precursor. A glass insert along with a removable PEEK stir paddlefor the cell were dried in a vacuum oven at 125° C. overnight. Theinsert with the amine, 1,2-dimethoxyethane and KH was loaded into eachPPR well, heated to 130° C., and pressurized with nitrogen to 50 psi. EOwas introduced at 130° C. and the reaction was stirred for 12 h at thattemperature. After cooling and venting, the insert was placed in aSavant SC250EXP SpeedVac® Concentrator for 1 h at 80° C. and 0.01 Torr.The resulting viscous surfactants are identified as Examples 7-9,respectively, and were tested for their properties without additionalpurification. The identity of the surfactants was confirmed by NMRspectroscopy.

Examples 10

Basic surfactant properties were characterized on the surfactants fromEXAMPLES 7-9, where the ethylene oxide (EO) content is 4, 3.5 and 8equivalents, respectively. Table 2 summarizes the results obtained.

TABLE 2 Comparison of basic surfactant properties of non-ethoxylatedamine-based molecules from EXAMPLES 4-6 with those of the correspondingethoxylated versions from EXAMPLES 7-9. COMPARATIVE COMPARATIVECOMPARTIVE EXAMPLE 7 EXAMPLE 2 EXAMPLE 8 EXAMPLE 3 EXAMPLE 9 EXAMPLE 4Corresponding EXAMPLE 7 EXAMPLE 4 EXAMPLE 8 EXAMPLE 5 EXAMPLE 9 EXAMPLE6 Surfactant Equilibrium 39 60 33 42 46 65 surface tension, mN/m Dynamic54 70 50 71 37 62 Surface Tension at 5 bbl/sec, mN/m Contact angle 64 8158 75 62 86 on polyethylene, degree Contact angle 75 91 70 101 88 102 onTeflon, degree Note: All tests done on aqueous solutions (0.1 wt %).

Other embodiments of this invention will be apparent to those skilled inthe art upon consideration of this specification or from practice of theinvention disclosed herein. Various omissions, modifications, andchanges to the principles and embodiments described herein may be madeby one skilled in the art without departing from the true scope andspirit of the invention which is indicated by the following claims.

What is claimed is:
 1. A nonionic surfactant with the following formula

wherein each R⁷ and each R⁸ independently is a monovalent moietycomprising 1 to 20 carbon atoms; each R⁹ independently is H, amonovalent moiety comprising 1 to 20 carbon atoms; and each tindependently is 1 to 20; each E independently is H or an N-functional,monovalent moiety of the formula—R²—(R³O)_(x)—R⁴ with the proviso that at least one E is not H, whereineach R² independently is a single bond or a divalent linking group; eachR³ is independently an alkylene moiety containing from 1 to 5 carbonatoms; each x independently is 1 to 100; and each R⁴ independently is Hor a monovalent moiety comprising from 1 to 8 carbon atoms.
 2. Anonionic surfactant with the following formula

wherein each R¹⁰ and each R¹¹ independently is a monovalent moietycomprising 1 to 20 carbon atoms; each R¹² independently is H, amonovalent moiety comprising 1 to 20 carbon atoms; and each qindependently is 1 to 20; each E independently is H or an N-functional,monovalent moiety of the formula—R²—(R³O)_(x)+R⁴ with the proviso that at least one E is not H, whereineach R² independently is a single bond or a divalent linking group; eachR³ is independently an alkylene moiety containing from 1 to 5 carbonatoms; each x independently is 1 to 100; and each R⁴ independently is Hor a monovalent moiety comprising from 1 to 8 carbon atoms.
 3. A paint,an ink, an adhesive, a coating, or an oil and gas recovery compositioncomprising the nonionic surfactant of claim 1 or claim 2.